The present invention, in some embodiments thereof, relates to an unclogging filter apparatus and, more particularly, but not exclusively, to an apparatus for unclogging an input filter for an agricultural emitter.
With population increase and climate changes, water resources are becoming more scarce, forcing farmers and gardeners to save water and direct irrigation to a close vicinity of target plants. Drip emitters, fed by an irrigation pipe of pressurized water, achieve such a directional irrigation.
Sometimes, dirt accumulates in the emitter and undesired flow restriction up to flow stopping occurs. To prevent entrance of dirt, the inlet opening may be shaped for filtering the water. However, while such a static filtering reduces dirt entrance to the emitter, the filter itself may become clogged. It is very difficult to clear barely accessible fine water passageways. Therefore, it is generally necessary to replace the whole emitter.
Sometimes emitters are installed into thin irrigation tubules. In such cases, dirt may block not only the emitter, but also it may also block the tubules.
U.S. Pat. No. 4,623,094 to Smeyers, discloses an internal notch filter that can be rinsed so that the particles retained by filtering notches are removed through the outlet by the flushing with the liquid. Smeyers also teaches a pre-filter having a diameter, which is larger than the diameter of the inlet. When the dripper is in use, the prefilter is applied against the entrance of the inlet and filters the large impurities contained in the liquid admitted into the dripper. When the dripper is not in use, the pre-filter is removed from the free end of the inlet. The pre-filter may consist of a sieve or diametral bars which stop large particles, such as vegetable fragments, from entering into the dripper.
U.S. Pat. No. 4,331,293 to Rangel-Garza teaches a micro-filter formed in the extreme lower part of a bored nipple pivot. Because of its location inside the hoses of dripper or sprinkling lines, the micro-filter will stop the particles which are in the flow of water from entering into the inside of the emitter, avoiding the obstruction of the emitter and at the same time, permitting all of the particles which could not enter into the emitter and which stayed in the dripper of sprinkling hoses, to be easily dislodged upon flushing the lines at their extreme ends, during the normal maintenance of the irrigation systems.
Additional background art includes U.S. Pat. No. 4,059,228 to Werner and European application EP1884157 to Schiedt and Belgian patent application BE895982.